Deputy Labour leader Harriet Harman has said the government must not allow political bias to influence and undermine the appointment of the next chair of the BBC Trust.

Harman has written a letter to culture secretary Sajid Javid, whose department is in charge of replacing Lord Patten, calling for a "consensual" recruitment process. She is understood to be keen for the DCMS to include other parties in that process.

"It is imperative that the appointment must be made on merit and not on party political lines," said Harman.

"[The BBC] is such an important organisation that it is imperative to avoid any perception of considerations of party politics, particularly ahead of a general election and ahead of [BBC] charter renewal," said the shadow culture secretary.

"There are different views about the role of the BBC within our political parties, but it is vital that the BBC gets the best person for the job who will fulfil their responsibilities in the best interests of the organisation and the licence fee payers."

The department of culture, media and sport is understood to have put out a tender to recruitment agencies to help with the process and canvas the widest range of candidates.

Harman called on Javid's department to be transparent about the mechanics for finding a successo, including asking the DCMS to publish a "clear process and timetable for selection".

"It must be an appointment that commands confidence and attracts widespread approval if that person is to take the BBC forward," added Harman.

The earlier frontrunner for the role is considered to be Sir Howard Stringer, the former Sony and CBS boss who is a non-executive director at the BBC.

Candidates include Dame Marjorie Scardino, the former chief executive of Financial Times-owner Pearson; former Ofcom chairman Colette Bowe; BBC Trust vice-chair Diane Coyle; Lady Wheatcroft, the Conservative peer and former editor of the European edition of the Wall Street Journal; and Lady Hogg, a crossbencher who is married to the former Tory cabinet minister Douglas Hogg and was once John Major's Downing Street policy chief.

Earlier this month, John Whittingdale, the head of a committee of MPs that will vet the next chair of the BBC Trust, warned Cameron against pushing any political agenda.

"The [BBC] is working hard to learn lessons from the horrific behaviour uncovered by the Savile scandal and seeking to address issues around executive pay, as well as grappling with the demands of an ever-changing technological landscape," said Harman. "This is a critical time for the BBC."

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